Magneto ignition apparatus.



J. L. MILTON.

MAGNET() www Patented May 19, 1914.

. Inv Ei TTU T EUR l... Mmmm @E 'ix An-TU E f5 JOHN Lewisy MILTON, or onrcaedinninors.

g Toall whom 'it may concern:

Be it known that I, J oi-IN L. Minton, a

"citizen of the United States, residing at Chicago, inthe county of Cook and State of Illinois, have invented a certain new and useful Improvement inMagneto Ignition Apparatus, (Case No. 5,) vof which .the followinggis a full, clear, coiilgise, and exact desoription, reference beinggliadto the accompanyingdrawings, forming a part of this specification.

. `My invention relates to magneto ignition apparatus, and has-ier its olo'ject' the provision of an inductor alternator' of `compact form, and one which at the saine time is capable of producing very desiralfilewetlects. .This compactness oiy design is secured by forming the laminated pole pieces Vsofas to tit lroughly within the confines of a circle. Each set of permanent field magnets comprises a series `oi magnets of differing lengths, theshorter" magnet oe-achset being placed at the outside andthe longer magnets toward the center or axis of rotation. Notwithstanding this generally circular arrangement of the field magnet, I provide in the laminated pole pieces a. large crosssectional area through which the luX 'of all of the permanent magnets may pass.

The cross-sectional area is gradually di# minished toward the outside until the point traversed by the flux of but a. single permanent magnet, this area is lquite* small 'jjnagnetic efficiency is not sacrificed evenV "and only sutcient for the purpose of con- "ducting the iiux from this single magnet. VThe result of this construction is that the though the design he well adapted for place ment in confined locations and in positions such as frequent-ly present themselves in automobile work, where, although the space is small, it is necessary to rotate the entire field magnet about. vthe axis of rotation in order to adjust or time the `position ot the spark relatively to the annular position of the engine cranks. These various features of my invention will be more readily understood by reference to the accompanying drawings, in whiehy Figure l is a view in front elevation of the magneto generator of my invention, certain parts hei-ng omitted and others broken away for the sake of clearness; Fig. 2 is a cross-sectional View taken on line 2-2 of Fig, l, and Fig. 3 is a detailed view showl l ynearer the center.

iviaeniiro IGNITION` APPARATUS.

Specification: of Letters Patent. Patented BIay 19, 1914. Application filed July l5, 19.08. Serial No. 443,603. l l l ing, in plan, the form of permanent. niagnets and indicating the manner of their connection to the pole pieces. I

Referring to the drawings, it will be seen that my inventioncontemplates bifurcated pole pieces l5 having an outline suhstan .tially like that indicated in Fig. l. These pole pieces when clamped together by means of the strips 2T. It will he noted that the outerinagnet oi each set is the shortest, and that each successive magi'iet toward the cen 'ter of the machine ris of slightly greater length than the next one outside. The pole pieces are stepped tocorrespond with this diiference in the length oil the permanent magnets of each set. Notwithstanding the fact that the permanent magnets toward the center are longer than those at the outside,

the vstill greater increase fin the outside width of the pole pieces is such that the cross-sectional area 'on the dotted line 29 is greater than on the line with anyother .permanenti magnet, thus providing for the greater luX which must traverse the pole .pieces at this point. It will be noted that the cross-sectional area is least on the line 30, since the flux from the single permanent 4magnet on lthe outside of the machine is correspondingly less than at any other point There is no winding upon the inductor or rotor member of the machine, the wind.- ings being confined to the yokes connecting the bifurcated pole pieces. It will be apparent to those skilled in the art that ifthe polarities of the permanent magnets be arranged as indicated in the drawings the magnetic linx will twice change its direction through each of the generator coils with 'with projections 26 to prevent the lateral movement of the magnets relatively to the each revolution of the rotor shaft. Each .manent bar magnets,

' of rotation,

reversal of the direction of iiux through the coils marks the peak of a wave of alternating current.

It will be understood by those skilled in the art that many modifications of the arrangements herein disclosed may be made without departing from the spirit of my invention, and I do not Wish therefore to be limited tothe precise details of these constructions. On the other hand, the scope of my invention is indicated in the accompa' nying claims.

In my copending application, Serial No. 357,041, filed February 12, 1907, I claim matter which is disclosed but not claimed in this application, viz., the general field structure, the general arrangement between the rotor and the field structure, thefield magnets of different lengths, and the means for mounting these'magnets. In my copending application, Serial No. 384,049, filed .July 16, 1907, I also claim matter which is disclosed but not claimed in this application, viz., the arrangement of the field windings between the polar projections on the magnetic members.

I claim-- 1 In a device ofthe class described, the combination of a rotor, two sets of pereach set comprising magnets of diiierent lengths, soft iron pole pieces surrounding the rotor and having a generally circular contour concentric with respect to the axis ofthe rotor, .said pole pieces -having stepped surfaces of engagement, and the sets of permanent magnets being located one on either side of the axis the shortest magnet of elch setl being located farthest from the axisbf rotation, and the other magnets of each set being arranged parallel with 'the shortest magnet and in the order of their length toward the axis of rotation, and means for holding the ends of the magnets in engage- 45 ment with said stepped surfaces'.

2. In a device of the class described, the combination of a rotor, two sets of per-l manent bar magnets, 'each set comprising magnets of different lengths, soft iron pole pieces surrounding the rotor ahd having agenerally circular contour concentric with respect to the axis of the rotor,fsaid pole :pieces having stepped surfaces of engagement and the sets of permanent magnets `ward the axis of rotation,

being' located one on either side of the axis of rotation, the shortest magnet of each set being located farthest from the axis of rctation and the other magnets of each set being arranged parallel with the shortest magnet and in the order of their length toand means for holdingthe ends of the bar magnets in engagement with. said steppedsurfaces, the cross-sectional area of the pole pieces op posite the ends of the permanent magnets varying as the number of magnets Wiese flux is conveyed therethrough.

3. In a device of the class described, the combination' of 'a rotor, two sets of longitudinally divided bar magnets with notched ends, the magnets of each set being of different lengths, soft iron pole pieces having stepped surfaces of engagement, said pole pieces surrounding the rotor and having a generally circular contour concentric with respect to the axis of rotation, means for holding the ends of the bar magnets in cngagement with the stepped surfaces of the pole pieces, the shortest magnet of each set being'located farthest from the axis of rotation, Vand the other magnets of each set being arranged parallel with the shortest magnet and in the order of their length toward the axis of rotation, the cross-sectional area, of the pole pieces opposite the ends of the permanent magnetsV varying as the number of magnets whose` fiux is conveyed therethrough.

4. In an inductoralternator,^the combination, with a rotor, of a field-magnet structure comprising two 'sets of 'permanent straight-bar magnets, each set comprising magnets of different lengths, pole pieces ar'- ranged to connect poles of like polarity of said magnets and having a generally circular contour concentric with respect to the axis of the rotor, one set of magnets being located on either sideof the axis of rotation, with the shortest magnet located farthest from the axis of rotation and the other magnets of each set arrangedvin the order of their length toward theaxis of rotation.A

In witness whereof, I hereunto subscribe my name this 8th day of July,1908.

'p JOHN LEWIS MILTON. Vitnesses; v v i LYNN A. 'Winnaars LEONARD W. NovANDER. v 

